Olivia Lua has become the fifth star of pornographic videos to die in three months since November.

The 23-year-old star of Sneaky Sex and Hostel XXX died in a Los Angeles rehabilitation centre over the weekend, after consuming a "cocktail of prescription drugs and alcohol", according to a statement from her agency.

Lua, who used the screen name Olivia Voltaire, had been battling drug addiction for some time.

She posted two photos with cryptic messages on her Twitter account last week.

"Much comment has recently been made on the number of adult stars having passed in the last year and with great sadness, we must inform that the list has grown longer," Lua's agency LA Direct Models said.

"We learned today that Olivia Lua passed away this morning - may she rest in peace.

"We learned today that she had returned to a different facility in West Hollywood after a relapse, approximately a week ago, at which she was found deceased this morning."